Transcript Passive Seismic: Recent advances

Hydraulic Fracturing:
Points and Counter Points
Fred Aminzadeh1,2
Felipe de Barros3
Nima Jabbari1,2,3
1USC
Petroleum Engineering Program
2USC Induced Seismicity Consortium (ISC)
3USC Civil and Environmental Engineering Department
Urban Water Institute
20th Annual Water Policy Conference
San Diego, CA
August 16, 2013
Isc.usc.edu
Summary
What is Hydraulic Fracturing (Fracking)
Fracking Risk Factors
Induced Seismicity
Monterey shale
Balance
Fracking: Overview
 Natural gas: good alternative for fossil fuels (less CO2
production)
 Shale Formation, low permeability, rich of natural gas (known as
Shale Gas)
 Unconventional vs. Conventional
 The Potential Gas Committee:
within five years the potential
reserves of shale gas has tripled
from 200 trillion cubic feet in 2006
to nearly 700 trillion cubic feet in
2010
 Tight formation => Stimulation
Methods to change the permeability
Shale plays in the USA (EIA)
(Hydraulic Fracturing)
What is Fracking
 Hydraulic fracturing is stimulating rock layers by a pressurized
liquid to facilitate release of gas and oil.
 It creates fractures from a wellbore drilled into reservoir
http://en.wikipedia.org/wiki/Hydraulic_fracturing
More on Fracking
Hydraulic Fracturing
Why worry?
 HF fluid = water and various chemical additives.
750 chemicals (toxic) in the HF fluids
The choice of the chemicals and quantities vary
according to site conditions & project needs
Commonly used chemicals:
 HF fluid: methanol, isopropanol, quartz, ethylene
glycol monobutyl ether, ethylene glycol, light
petroleum distillates and sodium hydroxide
 Recovered HF fluids  contaminated when in contact
with the shale.
 Accidental spill of the HF fluid (prior to injection or
recovered)
More on Potential Risk Factors
Contamination of ground water
Depletion of fresh water (Recovered fluid: 25-100 %)
Risks to air quality (CH4, VOC’s)
Migration of gases and chemicals to the surface
Surface contamination from spills and flow-back
Induced Seismicity
3000-8000 ft
Examples of Risk Pathways:
Groundwater Contamination
Figure 3. Schematic illustration of the conceptualization associated with S2,
showing multiple contaminant pathways stemming from the subsurface. The
HF fluid and other contaminants can travel toward groundwater aquifer
through failed well casing (A), fractures (B), and faults (C).
Rupture in the well!
Contamination of the
aquifer.
Figure 2. Conceptual illustration for surface to aquifer contamination pathway
(items 1 and 3).
Spill in the ground
surface! Contamination
of the vadose zone and
eventually the aquifer.
Contamination from Recovered HF Fluid
 Recovered HF fluids may become contaminated once they
are in contact with the shale.
 HF fluids extract heavy metals, hydrocarbons, natural
salts and radioactive materials from the shale.
 Recovered HF fluids may contain the following chemicals:
chloride, sodium, bromide, arsenic, barium and natural
occurring radioactive materials (NORM) such as uranium,
radon and radium [Rozell and Reaven, 2012] as well as
high TDS values (70,000 to 250,000 mg/L) [NETL, 2013]
Any accidental spill related to the HF fluid (prior to
injection or recovered) can pose risk to aquifers and
human health (many of these chemicals are carcinogenic)
Introduction to Induced Seismicity
fracture treatment / Fluid Injection / CCS
Increase in stress and pore Pressure
Decrease the stability of existing weak planes
(natural fractures, bedding planes)
slip and fail, similar to earthquakes along faults
slippages emit elastic waves (stimulated
seismicity)
Induced Seismicity Data Base
Models-IS Risk Maps
Preliminary Observations on Induced Seismicity
 The energy level which is released is large enough to be
recorded, but too low to directly create major seismic events,
 Real time monitoring of Micro-earthquake data can help mitigate
or reduce the risk of triggering large damaging earthquakes,
 We are looking into three test beds: San Joaquin Valley, CA,
Youngstown, Ohio and Blackpool, UK,
 Similar to the “Earthquake Hazard Maps”, IS hazard maps can
alleviate the concerns for IS risk of SFIP in the majority of cases,
 More modeling, statistical analysis and research needed to
substantiate some of the preliminary conclusions.
California Monterey Shale
 (EIA) estimates the Monterey/Santos play holds 15.4 bbo of shale resources; the
Bakken and Eagle Ford combined have about 7 bbo
 The Monterey shale is the primary source rock for the conventional oil reservoirs
found in the Santa Maria and San Joaquin basins in southern California.
California play full of complexities Monterey
Shale Continues to Tempt and Tease
www.aapg.org/explorer/2013/02feb/monterey_shale0213.cfm
http://www.aapg.org/explorer/2012/11nov/monterey1112.cfm
Monterey Shale Development, Pros and Cons
Benefits:
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Create more jobs: 512K to 2.8 million new jobs
Stimulate economy. GDP up by 2.6-14.3%
Global Energy Network
Increase personal income. Up by 2.1-10.0%
Boost State revenue. Tax growth $4.5-24.6B University of Southern California
Caveats:
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Exploratory study and preliminary results
Warrants further multi-dimensional studies
Need to examine: environmental issues,
Need to address technology challenges
The Monterey Shale
& California’s
Economic Future
March 2013
http://gen.usc.edu/assets/001/84954.pdf
Should Fracking Stop?
A drilling operation in Bradford County, PA:
Extracting gas from shale increases the availability of this
resource, but the health and environmental risks may be too high.
POINT
COUNTERPOINT
Yes, it’s too high risk
Natural gas extracted from shale
comes at too great a cost to the
environment,
No, it’s too valuable
Fracking is crucial to global economic
stability; the economic benefits
outweigh the environmental risks,
Say Robert W. Howarth and Anthony Ingraffea.
says Terry Engelder.
http://www.nature.com/nature/journal/v477/n7364/full/477271a.html
Concerns to Address
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Balance
Water supply contamination
Increased induced seismicity
Land-use challenges
Water-use challenge
Potential to overwhelm community infrastructure
Continued reliance on fossil oil
Possible Steps
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More Science
More Disclosure
Understand economic impacts of extreme measures
Improve Education/Outreach
Listen to both sides
To Frack or not to Frack, That is the Question
Science is the Answer: Vincit Veritas (Truth Prevails)
Summary
What is Hydraulic Fracturing (Fracking)
Fracking Risk Factors
Induced Seismicity
Shale Resources and the Role of Fracking in their
Development
Monterrey shale and its potential economic
impacts in California
Technology requirements for Monterrey shale
development
Where do we go from here
Thanks!